Add "Back to Top" in README

[alizahh-7]

Description:
The "⬆️ Back to Top" link located at the bottom of the README

Steps to Reproduce:

Scroll to the bottom of the README.

Click the "Back to Top" link.

Expected Behavior:
Clicking the link should bring the reader back to the beginning of the README, allowing smoother navigation throughout the document.

[github-actions]

Thank you for raising this issue!

We'll review it as soon as possible. We truly appreciate your contributions! ✨

Meanwhile make sure you've visited the README.md, CONTRIBUTING.md, and CODE_OF_CONDUCT.md before creating a PR for this. Also, please do NOT create a PR until this issue has been assigned to you. 😊